Frangible safety device



March 5, 1935. R. w. TRYON El AL FRANGIBLE SAFETY DEVICE Filed Nov. 25, 1930 2 Sheets-Sheet 2 Patented Mar. 5, 1935 r I UNITED STATES PATENT. OFFICE 1,993,301 FRAiNGIBLE SAFETY DEVICE Richard W. Tryon and George M. Booth, Elizabeth, N. J., assignors to Standard Oil Development Company, a corporation of Delaware Application November 25, 1930, Serial No. 498,098 11 Claims. (Cl. 220-89) This invention relates to improvements in autobe used is connected with it through a pipe 18 matic release devices of the frangible type for opening into casing 6. A manually operable containers which may be subjected to excessive valve 19 of any suitable type is installed in this pressure. The principal object of the invention pipe. Casing 6 is also connected with pipes 20 is to provide a release device in which the frangiand 21. Pipe 20 is coupled with fitting 1'7 and 5 ble element is adapted to yield on direct tension. pipe 21 with an opening in the upper casting 3. This is applied by pressure acting on a member These pipes may join at 22 and communicate with of large cross-sectional area carried by the frangia look-box, or other suitable indicating device 23. ble element. Other objects of the invention are The frangible cylinder is preferably made of to minimize the danger of corrosion, distortion steel. The extent to which the cylinder is weak- 10 and fatigue of metal, and the like, which may ened by cutting away at the section 8 is determake release devices of the frangible type inopmined by the amount of pressure which the device erative. The invention will be fully understood is to withstand. It will be observed that the area from the following description, read in connection of diaphragm 13 is very large compared with the with the accompanying drawings in which cross-sectional area through'sectlon 8. Accord- 15 Fig. 1 is a vertical section through a preferred ingly pressure exerted on the lower face of the form of the invention; diaphragm has a multiplied eii'ect on the frangi- Fig. 2 is a vertical section through the frangible ble element. Section 8 may therefore be made element of Fig. 1, and relatively thick and thereby resistant to failure Fig. 3 is a vertical section through a modified through corrosion, but the section will neverthe- 20 form in which a liquid is used for transmitting less yield at the required pressure. pressure. Diaphragmdit is made of some strong, flexible In the drawings (Figs. 1 and 2)-, reference numaterial, preferably lead supported by a thin meral 1 denotes a casting having an annular layer of copper. Other materials may be used,

flange 2. Acorresponding casting'3 has an annuwhich will satisfy the essential requirements of 25 l r flan e 4. The flanges are secured together strength sufficient to resist rupture at the mary bolts gin and resilience or flexibility sufficient to per- Within the casing 6 thus formed, there is promit deformation. The backing plate 14 is best vided a frangible element, which is preferably in made of steel. It should be heavy and cover as the form of a hollow cylinder 7 threaded exterimuch of the diaphragm area as is practical. 30

orly at both ends. The cylinder is indented or The operation of the device is as follows: cut away at an intermediate portion to form a When the pressure in the container, as transweakened section 8. Above and below this secmitted through pipe 18, exceeds the value which 151011 the y e 7 ar ie hexagonal flanges 9 the frangible element 7 is designed to withstand,

and 10. that element is ruptured at section 8 by the up- 35 Casting 1 has a central aperture 11 defined by ward pull or tension of the diaphragm 13. Pres- & i Flange 10 i Seated in his rim in such sure is thereupon relieved through the pipes 20 manner as to prevent rotation of the flange. A and 21, gas or liquid escaping through the rupflexibly mounted diaphragm or disc 13 has a centured section and the separated ends of cylinder 0 tral opening which fits over cylinder 7 and rests '7. The indentation 15a of diaphragm 13 gives it upon the upper side of flange 9. The outer marenough flexibility to rise until nut 16 strikes gin of diaphragm 13 is clamped between flanges against the upper part of casting 3. Corruga- 2 and 4 so as to make a fluid-tight joint with tion or other irregular conformation may be used them. A backing plate 14 rests upon the upper to give an equivalent effect.

surface of disc 13. The, plate has an annular The operator will detect the failure of the 45 raised portion 15 to which the diaphragm condevice by observing the look-box 23, or other forms, as at 15a. suitable signal that may be supplied. Valve 19 The frangible element described 'above is held will then be closed and the safety device placed in place by a nut 16 screwed on the upper end in operative condition. y

0 of cylinder '7 within casing 6, and by a fitting 1'7 In the form of the invention shown in Fig. 3 screwed on the lower end of that cylinder outside a liquid such as glycerin, heavy petroleum oil, of easing 6. Gaskets 16a and 16b, arranged re- 01' the like is used to protect the frangible elespectively beneath nut 16 and-flange 10 make the ment from contact with corrosive gases or liquids. mounting of cylinder '7 fluid-tight. The structure of the safety device is the same as 65. The container on which the release device is to in Figs. 1 and 2. However, the pressure transll mitting line 24 from the vessel to be protected is formed with a trap in which liquid is retained. The device operates as previously described, the only difference being that the pressure is transmitted through the liquid contained in trap 25.

This arrangement is desirable when very corrosive substances are likely to come in contact with the frangible element. Other means of protecting the element may be adopted such as anti-corrosion paints and the like.

The foregoing description is illustrative only and various changes and alternative arrangements may be made within the scope of the appended claims, in which it is our intention to claim all novelty inherent in the invention as broadly as the prior art permits.

We claim:

1. A pressure release device, comprising a casing, a flexibly mounted diaphragm therein, a backing plate supporting the diaphragm, an elongated member having a weakened section connected to the diaphragm and plate, and means for transmitting pressure to the diaphragm.

2. Apparatus according to claim 1 in which the plate has surface irregularities to which the diaphragm conforms.

3. Apparatus according to claim 1 in which the member having a weakened section is a hollow cylinder indented circumferentially near its middle. a

4. In a pressure release device a flexibly mounted supp rt having a separate frangible element secured thereto and adapted to be ruptured by displacement of the support, said support comprising a plate having surface irregularities and a flexible diaphragm conforming to those irregularities.

5. Apparatus according to claim 4 in which the diaphragm is held marginally by the abutting surfaces of flange castings, so that the diaphragm forms a central partition within the castings, and a separate frangible element is mounted for movement with the diaphragm.

6. A pressure release device comprising a casing and an elongated member, having a weakened section, within the casing and secured thereto at one end, a flexibily mounted diaphragm secured in the casing, means connecting the other end of the elongated member with the diaphragm, means for admitting fluid under pressure into the casing, and means for venting said fluid when its pressure is suflicient to causethe rupture of the weakened section.

7. A pressure release device comprising a casing and an elongated hollow member, having a weakened section, within the casing and secured thereto at one end, a flexibly mounted diaphragm marginally secured in the casing, means connecting the other end of the elongated hollow member with the diaphragm, means for admitting fluid under pressure into the casing, a vent pipe connected to the casing and means for venting said fluid through the hollow member and the vent pipe, when the pressure of the fluid is sufllcient to cause the rupture of the weakened section.

8. A pressure release device comprising a casing, an elongated hollow member therein having a weakened section, a flexible diaphragm mounted in the casing, means for securing the hollow member to the casing and to the diaphragm, inlet and outlet vent pipes in general alignment with the hollow member, means for admitting fluid under pressure into the casing whereby when the predetermined pressure is exceeded the pull on the diaphragm will cause the weakened section of the hollow member to rupture and permit the discharge or fluid through the vent pipes.

9. Apparatus according to claim 8 in which the diaphragm is marginally secured in the casing and is provided with a backing plate.

10. A pressure release device comprising a casing, a frangible rod therein rigidly connected at one end to the casing, a diaphragm mounted in the casing and connected to the other end 01' the frangible rod, means for transmitting fluid pressure to the diaphragm whereby the diaphragm is flexed away from the casing, and means for venting pressure when the rod breaks owing to the pull of the diaphragm.

11. Apparatus according to claim 10 in which the frangible rod is hollow and has two circum-. ferential flanges between which the walls of a central opening of the diaphragm are engaged.

RICHARD W. TRYON'.

GEORGE M. BOOTH. 

